org.apache.arrow.c

Class ArrowArrayStream

java.lang.Object

org.apache.arrow.c.ArrowArrayStream

All Implemented Interfaces:

AutoCloseable, BaseStruct

public class ArrowArrayStream
extends Object
implements BaseStruct

C Stream Interface ArrowArrayStream.

Represents a wrapper for the following C structure:

 struct ArrowArrayStream {
   int (*get_schema)(struct ArrowArrayStream*, struct ArrowSchema* out);
   int (*get_next)(struct ArrowArrayStream*, struct ArrowArray* out);
   const char* (*get_last_error)(struct ArrowArrayStream*);
   void (*release)(struct ArrowArrayStream*);
   void* private_data;
 };
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ArrowArrayStream.Snapshot Snapshot of the ArrowArrayStream raw data.

Method Summary

Modifier and Type	Method and Description
static ArrowArrayStream	allocateNew(BufferAllocator allocator) Create ArrowArrayStream by allocating memory.
void	close() Close to release the main buffer.
void	getNext(ArrowArray array) Get the next batch in the stream.
void	getSchema(ArrowSchema schema) Get the schema of the stream.
void	markReleased() Mark the array as released.
long	memoryAddress() Get memory address.
void	release() Call the release callback of an ArrowArray.
void	save(ArrowArrayStream.Snapshot snapshot) Write values from Snapshot to the underlying ArrowArrayStream memory buffer.
ArrowArrayStream.Snapshot	snapshot() Take a snapshot of the ArrowArrayStream raw values.
static ArrowArrayStream	wrap(long memoryAddress) Create ArrowArrayStream from an existing memory address.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

wrap

public static ArrowArrayStream wrap(long memoryAddress)

Create ArrowArrayStream from an existing memory address.

The resulting ArrowArrayStream does not own the memory.

Parameters:

memoryAddress - Memory address to wrap

Returns:

A new ArrowArrayStream instance

allocateNew

public static ArrowArrayStream allocateNew(BufferAllocator allocator)

Create ArrowArrayStream by allocating memory.

The resulting ArrowArrayStream owns the memory.

Parameters:

allocator - Allocator for memory allocations

Returns:

A new ArrowArrayStream instance

markReleased

public void markReleased()

Mark the array as released.

memoryAddress

public long memoryAddress()

Description copied from interface: BaseStruct

Get memory address.

Specified by:

memoryAddress in interface BaseStruct

Returns:

Memory address

release

public void release()

Description copied from interface: BaseStruct

Call the release callback of an ArrowArray.

This function must not be called for child arrays.

Specified by:

release in interface BaseStruct

getSchema

public void getSchema(ArrowSchema schema)
               throws IOException

Get the schema of the stream.

Parameters:

schema - The ArrowSchema struct to output to

Throws:

IOException - if the stream returns an error

getNext

public void getNext(ArrowArray array)
             throws IOException

Get the next batch in the stream.

Parameters:

array - The ArrowArray struct to output to

Throws:

IOException - if the stream returns an error

close

public void close()

Description copied from interface: BaseStruct

Close to release the main buffer.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface BaseStruct

snapshot

public ArrowArrayStream.Snapshot snapshot()

Take a snapshot of the ArrowArrayStream raw values.

Returns:

snapshot

save

public void save(ArrowArrayStream.Snapshot snapshot)

Write values from Snapshot to the underlying ArrowArrayStream memory buffer.